Hi! I've got a bit of a dodgy knee and I was wondering would it be better to use knee wraps whenever going heavy with squats or only use it when it's flared up? It tends to get bad if i'm maxing my C&J or doing near maximal squating.
many thanks for your time and any advice!

Wrapping knees to avoid pain is a dark art. I'd look to get them healthy and use wraps before they hurt not after. I avoid political discussions on things like belts, wraps etc but I will say this, wraps won't make you weaker but messed up connective tissue will.